So you say they have pushed it up. Let's take a rifle and caliber that has defeated you and one that you have recently posted about in at least two forums. The 6.5x55 Swede. You even said you are going to reside to shooting the 1400 to 1800-1900 fps with it and be happy. Now my "cuz" flat out beat your threshold with his Swede using the 130 Kurtz bullet. I'd say a 1/2 inch group at 100 yards at nearly 2300 fps in that fast twist isn't just pushing up the threshold. You do realize that a threshold is no moveable, or least by not much? How about a door threshold? Ever stop to think why it's called that? Before you address the above Swede shooting that test was repeated many times, just not photographed nor talked about. Also not photographed or talked about is the 180 grain 30 Sil at jacketed velocities into very small groups none larger then 1/2 inch and out of both 10 twist, 11 twist, and 12 twist. 45 2.1 has been doing it regularly out of the Ruger Scouts. Cuz actually saw that happen and also shot almost the same small groups with it.
Here's another recent shot rifle that just didn't push up your threshold, but soundly beat it again:
Rifle: 1909 Argentine
Groove: .3110
Brass: 30-06 Rem sized down to 7.65 Argentine with no special work done to it.
Powder: Alliant RL-22
Charge: 45.0 grains
Primer: CCI Large Rifle Standard (I don't like them)
Temperature: 44 Degrees
Humidity: 43%
Wind: Less then 5 mph head on.
Attitude: 2200 feet
Shots Fired: 10
Average Velocity: 2239 fps
ES: 68
SD: 25
Group Size: 1 inch
Lube: Soap Lube
Gas Checks: Hornady
Chrono Distance: 9 feet 1.5 inches
Then their Cuz's little SAKO 7mm-08 shooting the LEE 130 grain bullet (a non-fitted bullet) into 3/4-1 inch groups at 2640 fps.
You have a selective memory Larry.
I will address your "If there is not an RPM threshold then how is it most cast bullet loads with fast and medium burning powders lose accuracy when they exceed 140,000 RPM" That's a well duh question. To reach that rpm range you have to hit the bullet pretty hard and you know very well that the fast powder is especially not the one to do so with. Do I have to tell you why? So according to you all fliers are because of the threshold? You ever think that those fliers may be from poorly cast bullets. That brings up the member casting better then your 1.1 grain variance in recent posts in more then one place on this forum. You know very well that there are many things that can ruin or prevent a bullet from starting straight into the bore.
Waco done very well for being a young fellow and with a mediocre rifle (not so much the rifle, but it's terrible throat) for the first time out doing this.
Let me know when you can cast all your bullets within a .1 grain variance. Don't forget you're the one that posted your variance weights in three forums that I know of, so I'm not making inane statements....you made them.